A phase I-II trial of fixed-dose carboplatin and escalating paclitaxel in advanced ovarian cancer

We conducted a phase I-II study with escalating paclitaxel doses plus carboplatin at a fixed dose for previously untreated patients with advanced ovarian cancer in order to define the maximum tolerated dose. Eligible for the study were women with a histologically confirmed diagnosis of ovarian cancer stage III-IV according to the FIGO classification. In the first phase of the study, 6 patients were allocated escalating paclitaxel doses with fixed-dose carboplatin in order to establish the maximum tolerated dose. The starting dose of paclitaxel was 150 mg/m2 given after carboplatin (300 mg/m2) every 4 weeks for a total of six courses. The paclitaxel dose step was 25 mg/m2 up to 250 mg/m2. The study then progressed to a phase II trial using the maximum tolerated paclitaxel dosage reached during the escalating dose phase. A total of 27 patients entered phase I and 23 phase II. Neurotoxicity was observed in 47 patients (94%; 29 grade 1, 17 grade 2, 1 grade 3, according to the WHO classification). The intensity of neurotoxicity tended to be dose related: out of the 15 patients who received < or = 200 mg paclitaxel, a total of 14 grade 1, but no grade 2 or 3 neurotoxicities, were observed. The frequency of grade 1, 2 and 3 neurotoxicity was 15, 17 and 1, respectively, in the 35 women who received > or = 225 paclitaxel +300 mg carboplatin. There was no clear relationship between median WBC and platelet nadir and dose level. Among other toxicities, alopecia was observed in all 50 cases, hypersensitivity in two (4%) and myalgia in 41 (82%; 34 grade 1 and 7 grade 2). These frequencies tended to increase with the dose, but the relationship was not statistically significant. The overall response rate was 78% (39/50) with a complete response rate of 62% (31/50). In conclusion, this study suggests that carboplatin and paclitaxel can be administered safely to patients with advanced ovarian carcinoma. The maximum dose reached was 250 mg/m2 paclitaxel and 300 mg/m2 for carboplatin, but from a clinical point of view the maximum paclitaxel dose we would consider safe is 225 mg/m2.